The present invention relates to components for ink-jet cartridges, and techniques for constructing ink-jet print cartridges.
Ink-jet printers are in widespread use today for printing functions in personal computer, facsimile and other applications. Such printers typically include replaceable or semi-permanent print cartridges which hold a supply of ink and carry the ink-jet printhead. The cartridge typically is secured into a printer carriage which supports one or a plurality of cartridges above the print medium, and traverses the medium in a direction transverse to the direction of medium travel through the printer. Electrical connections are made to the printhead by flexible wiring circuits attached to the outside of the cartridge. Each printhead includes a number of tiny nozzles defined in a substrate and nozzle plate structure that are selectively fired by electrical signals applied to interconnect pads to eject droplets of ink in a controlled fashion onto the print medium.
Multicolor cartridges are known which have multiple ink reservoirs and multiple printhead nozzle arrays, one of each for each different color of ink. A manifold structure is typically employed to direct the inks of different colors from the respective reservoirs to corresponding printhead nozzle arrays. The cartridges typically include a body structure to which the printhead structure is attached. Typically the body structures and manifolds for multicolor cartridges have been assembled from multiple plastic parts, which are then bonded together by techniques such as ultrasonic welding or adhesives. Leaks and mislocation of the respective parts are commonly encountered problems.
One method which has been utilized to economically produce cartridges is to form the body and manifold as a unitary one-piece structure fabricated of a plastic material using an injection molding process, as described in U.S. Pat. No. 6,260,961, xe2x80x9cUnitary One-Piece Body Structure For Ink-Jet Cartridge.xe2x80x9d A lid is then attached to the unitary body to cover the compartments. To form the manifold region of the cartridge adjacent to the printheads, a mold slide insert may be utilized, resulting in a mold access hole in the cartridge body that must be sealed with a plug. To optimize air management, facilitate ink fill, and help prevent printhead deprime, the plug may have sculpted protuberances which extend into the cartridge body to form complex ink channels.
To prevent ink leaks, it is important that the plug form a reliable seal with the cartridge body. The seal must withstand prolonged contact with chemically aggressive inks, and must mechanically support the plug protuberances forming the ink channels. The seal may be subjected to significant stress during subsequent manufacturing steps, such as during ultrasonic welding of the cartridge lid to the cartridge body. The attachment process of the plug to the cartridge body must also not add undue manufacturing costs.
One cost effective method of bonding plastic parts together is with heat cured adhesives. Bonding plastic parts together with heat cured adhesives can be problematic, however, due to difficulties encountered in heating the adhesive. The plastic parts being joined can obstruct direct heating of the adhesive by hot air or infrared heating methods. Heat must then be transferred through one or both of the surfaces being bonded. Heat transfer through plastic is often poor and elevated temperatures and lengthy processing times may be required to obtain sufficient cure of the adhesive. The application of heat may melt, distort the dimensions or change the surface characteristics of the plastic. The long cure times can make the hot air process costly to scale up for high volume manufacturing.
There is therefore a continuing need for ink-jet cartridge components and assembly methods that are economical and reliable.
A side plug for an ink-jet cartridge body, and methods of attaching the side plug to the cartridge body, are disclosed. The side plug seals a mold access hole in the cartridge body. The side plug is preferably formed of a carbon fiber filled PET (Polyethylene Terephthalate) material; the carbon content of the side plug allows microwave curing of the epoxy adhesive used to attach the side plug to the cartridge body. The side plug may have sculpted protuberances which extend into the cartridge body to form complex ink channels.